[johndoesecond]

I'VE GOT IT ... so I'll try to satisfy some of your curiosity.

1. Conceptually, collections are more similar to tags than to (traditional) folders, even if they look more like folders. You can create a collection, then you select the books/documents you want to “associate” (add) to that collection. But differently from the old-time folders, each book/document may be associated to more than one collection. (So, if you were ER-relationally fluent, you’d know enough just by hearing that basically you can have many-to-many relation among books and collections).

2. The PDF zoom-and-pan support is neat. By pressing “Aa” button, you can pick the zoom size (among the options: “fit-to-screen” (which is default), “150%”, 200%”, “300%”, “actual size”); then a zoom box appears which you have decide where to put on the page and then click to zoom. After that, the scrollbars appear (horizontal and vertical, depending on the level of zoom and on the content to pan) and you can pan with the joystick. With some limited testing, to my knowledge the pan & page refresh is ... as fast as it can get under the circumstance (viz. eInk refresh rate).

3. I might be hallucinating, but the new standard font really seems clearer, neater and creates the feeling of a greater contrast, maybe it's even "bolder". Probably they’ve addressed and tweaked some of the antialiasing & C. issues someone has talked about in the past. It’s a great improvement for the overall readability!

4. I have a DXi and I'm living in Europe, so my Kindle's browsing was limited only to Wikipedia. But now, I can browse, well, just everywhere. (I hope this one isn’t a “bug” that inadvertently slipped into this update, … so, please, Europeans and non-US Kindle owners out there: psst! … don’t mention it to Amazon!)

5. Features like “social networking” and “popular highlights” may be cool to someone, but I’m just not that kind of guy, so don’t expect me to be too enthusiast about that, though I see some possibly interesting things there.

There seem to be some other minor changes and tweaks as well, but some may well just be mirages I'm seeing, as this things happen when you’re sort of a wonkishly satisfied with a device, as I am.

My final verdict?:
I might have not sounded too enthusiastic while trying to be technically accurate above, so ... wow!, … just wow!